C *2° 3 
IV. On the Production of artificial Cold by Means of Muriate of 
Lime. By Mr. Richard Walker. Communicated by Henry 
Cavendish, Esq. F. R. S. 
Read January 22, 1801. 
The subject of the means of producing artificial cold, or the 
constitution of frigorific mixtures, I had considered as exhausted, 
in the Papers I have already had the honour to lay before 
this Society : so far as relates to that part of the subject which 
consists in generating artificial cold without the use of ice , it 
still remains so with me, having nothing new to offer. 
A considerable acquisition however having been made, since 1 
my last Paper “ On the best Methods of producing artificial 1 
Cold,”* by the discovery that a neutral salt, but little known, 
or attended to, by chemists before, produced extraordinary 
effects of this kind with ice, it could not fail of attracting my 
attention. 
Since the time I first became acquainted with this circum- 
stance, I have, as opportunity offered, been engaged in making 
a variety of experiments with this salt, which I flatter myself, 
if the Society have not already received a communication on 
the subject, may not prove unacceptable. 
Before I relate my own experiments-, it may be proper to 
premise a short account of those of Mr. Lowitz, the author of 
the discovery. 
• Phil. Trans, for 1795. p. 270* 
